Comparison of carcinogenic potential of alternative tobacco products. A systematic review.

Objective: This study attempts to summarize current knowledge about the carcinogenic potential of alternative tobacco products: electronic cigarettes (ECs), heat-not-burn (HnB) cigarettes and snus/nicotine pouches (NPs). We focus on determining the effect of such products on epigenetic alteration, especially for genes and pathways which are fundamental for cancer development.

Methods: The literature was searched in PubMed, Embase and Scopus databases using the combination of terms: 'ENDS', 'electronic cigarette', 'e-cigarette', 'heat-not-burn cigarette', 'heated tobacco product', 'snus', 'nicotine pouch', 'cancer', 'epigenetic changes', 'DNA damage', 'carcinogenesis' in July 2025.

Results: Analyzed studies confirmed the effect of both ECs and HnB products on DNA damage induction, DNA repair capacity reduction, miRNAs expression, global DNA methylation status and histone modifications. In addition, snus/NPs use leads to induction of DNA damage and changes of the expression of genes associated with oxidative and cellular stress, DNA damage, cell growth and proliferation.

Conclusions: Cell-based and animal-based models confirmed some carcinogenic potential of ECs, HnB cigarettes and snus/NPs, as well as effects of ECs and HnB on epigenetic changes, which may predispose to cancer development. However, there is only a limited number of studies on such effect for snus/NPs and most of them describe their effect on the induction of DNA damage, cell growth and proliferation, which may increase probability of malignant cells transformation. Therefore, to fully explain the carcinogenic potential of such products, a comprehensive clinical studies for healthy exclusive ECs, HnB products and snus/NPs users and patients with tobacco-specific cancers should be carried out in the future.